Links:
Demonstrates User Instructions
http://www2.slac.stanford.edu/comp/winnt/backup/vssrestore.htm
Disable "Restore" button or "Previous Versions" Tab:
http://support.microsoft.com/kb/888603
Possible Hotfix Supplement for above KB
http://support.microsoft.com/kb/925066
Notes:
o Enabling Shadow Copies DOES NOT require a reboot of the server...
o The "Previous Versions" tab will not show up until after the first
shadow copy has taken place.
o After enabling Shadow Copies, you can choose the "Create Now"
button to quickly create an initial Shadow Copy.
o To quickly restore a file as an administrator, navigate the
filesystem thru the administrative shares. This will also give
access to files that are not directly shared out thru a shared
folder (eg. \\localhost\c$).
o Both the Copy and Restore Actions DELETE that copy of the data.
So once you have decided to Copy the information to another
location or you have decided to restore the information to the
original location, that Shadow Copy is removed from the list and
CANNOT be restored or copied again.
NOTE: On Windows XP SP2 and Windows Server 2003 R2 SP2, this
behavior cannot be reproduced...
o The client software for Shadow Copies of Shared Folders is installed
on the server: %systemroot%\system32\clients\twclient
The client software refers to shadow copies as "previous versions";
this was done to make the concept clearer for end users.
o You can browse the entire shadowed copy of the filesystem by choosing
to view a 'point in time' directory, from that view, you can use the
up, back, etc. browse buttons to browse the filesystem during that
point in time snapshot... To quickly view a folder, just double-click
the directory in the previous versions display.
o The default schedule will be 7:00 A.M. and 12:00 P.M. on weekdays.
Technical:
o 300Mb is initially allocated for Shadow Copies unless more is
required.
Shadow Copy Schedule (from Scheduled Tasks)
name.....: ShadowCopyVolume{d79ce4f4-fe42-11da-a09e-806e6f6e6963}
run......: c:\windows\system32\vssadmin.exe Create Shadow /AutoRetry=5
/For=\\?\Volume{d79ce4f4-fe42-11da-a09e-806e6f6e6963}\
start in.: %systemroot%\system32
run as...: NT AUTHORITY\SYSTEM
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Shadow Copies Command Line
You can see how much space is currently being used by typing:
vssadmin list shadowstorage
If you want to reduce the shadow copy footprint and reclaim some serious space,
you can type something like:
vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=500MB
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Remove "Previous Versions" Tab
When the Shadow Copies of Shared Folders feature is enabled on your server, the
Previous Version tab is present on the Properties dialog. To remove the Previous
Version tab for all objects, un-register the twext.dll library:
regsvr32 /u twext.dll
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Shadow Copies of Shared Folders
You can access the server portion of Shadow Copies of Shared Folders through
the Shadow Copies tab of the Local Disk Properties dialog box. Alternatively,
open Computer Management, in the console tree, right-click Shared Folders,
select All Tasks, and click Configure Shadow Copies.
You can use the Disk Management snap-in to manage Shadow Copies of Shared
Folders on remote servers as well. In the Computer Management console tree,
right-click Disk Management, point to All Tasks, and then click Configure
Shadow Copies.
The client software for Shadow Copies of Shared Folders is located on the
server and must be deployed to client computers. You can access the client
view of shadow copies through the Previous Versions tab of the Properties
dialog box of the shared file or folder.
In the Shadow Copies settings, the "Storage Area" Specifies the volume where
the shadow copies are stored. The default setting is the volume that contains
the source files. It is recommended that you use a separate volume on another
disk to provide better performance for heavily-used file servers. You can
only change the storage volume when there are no shadow copies present. If
you need to change the storage volume for a volume that has already been
enabled, you must first delete all of the shadow copies on that volume.
A new button has been added to the Shadow Copies tab for Windows Server 2003
with Service Pack 1 (SP1). You can use the Revert button to revert an entire
volume back to an earlier point in time. Reverting the entire volume will undo
any changes that were made to files and folders on the volume since the selected
snapshot was taken. If you revert a volume, you cannot undo the action later.
You should not use Revert on volumes that contain data stores like Active
Directory or Exchange.
When you restore a file, the file permissions will not be changed. Permissions
will remain the same as they were before the restore. When you recover a file
that was accidently deleted, the file permissions will be set to the default
permissions for the directory.
When storage area limits are reached, the oldest shadow copy will be deleted
and cannot be retrieved.
There is a limit of 64 shadow copies per volume that can be stored. When this
limit is reached, the oldest shadow copy will be deleted and cannot be retrieved.
Shadow copies are read-only. You cannot edit the contents of a shadow copy.
You can only enable Shadow Copies of Shared Folders on a per-volume basis; that
is, you cannot select specific shared folders and files on a volume to be copied
or not copied.
Do not enable shadow copies on volumes that use mount points. The mounted drive
will not be included when shadow copies are taken. Enable shadow copies only on
volumes without mount points or when you do not want the shared resources on the
mounted volume to be shadow copied.
Do not schedule copies to occur more often than once per hour. The default
schedule is 7:00 A.M. and 12:00 noon, Monday through Friday. If you decide that
you need copies to be taken more often, verify that you have allotted enough
storage space and that you do not take copies so often that server performance
degrades. There is also an upper limit of 64 copies per volume that can be
stored before the oldest copy is deleted. If shadow copies are taken too often,
this limit might be reached very quickly, and older copies could be lost at a
rapid rate.
Use an allocation unit size of 16 kilobytes (KB) or larger when formatting a
source volume on which Shadow Copies of Shared Folders will be enabled. If you
plan to defragment the source volume on which Shadow Copies of Shared Folders
is enabled, it is recommended that you set the cluster allocation unit size to
be 16 KB or larger when you initially format the source volume. If you do not,
the number of changes caused by defragmentation can cause previous versions of
files to be deleted. If you require NTFS file compression on the source volume,
you cannot use an allocation unit size larger than 4 KB. In this case, when you
defragment a volume that is very fragmented, you may lose older shadow copies
faster than expected.
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Shadow Copies of Shared Folders help file is located in the following location:
%systemroot%\help\twclient.chm
The client software for Shadow Copies of Shared Folders is installed on the
server by default in the following location (copy this to a share for users):
%systemroot%\system32\clients\twclient\
%systemroot%\system32\clients\twclient\x86\twcli32.msi
The client software refers to shadow copies as "previous versions"; this was
done to make the concept clearer for end users. Installing this client software
allows access to previous version thru a tab on the properies dialog of a file
in a share, thus:
righ-click the file, choose properties, select Previous Versions tab
To access previous versions of files, you must traverse the shadowed filesystem
thru a shared path, as an administrator, you can access mass previous versions
by using the root administrative share (eg: \\localhost\c$).
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The client computer user interface (UI) shows only previous versions that are different from the current version. If your file hasn't changed from the previous versions that are stored on the server, then the client UI will not show any previous versions.
I'm logged on locally to the server. How do I access shadow copies? This feature requires the Common Internet File System (CIFS) file sharing protocol to work—even if you are working on a server that stores shadow copies locally. Therefore, to see previous versions, loop back: for example, from Start, Run, connect to \\localhost\c$. This will enable the client running on the server to access previous versions.
For heavily loaded servers, you should dedicate a disk for shadow copy storage. This will eliminate extra disk head seeks caused by the copy-on-write algorithm.
On Windows Server 2003 SP1 revert is not possible for the boot and system volumes.
Two command-line tools enable you to administer shadow copies using scripts. "Vssadmin" lets you create shadow copies and configure settings for the shadow copy storage area. "Schtasks" lets you create and configure scheduled tasks. Using these tools you can automate every administrative task involving shadow copies.
Shadow Copies are stored in a hidden folder named "System Volume Information". This volume is accessible only to the built-in system account on your server, not to administrators.
Shadow copies use a minimum of 100Mb of disk space.
You might be wondering where shadow copies are stored on a volume. If you create a new 5,000 MB data volume E:, enable shadow copies on the volume, and click Create Now to generate shadow copies immediately (even though there are not files yet on your volume), then, when you select the E: drive in My Computer, you should see around 4,900 MB of free space. In other words, shadow copies immediately use the minimum 100 MB allocated to it the first time they operate. But your drive is still empty when you open it in Windows Explorer. If you use Tools?Folder Options?View to show hidden files and unhide hidden system files, you'll see a folder named System Volume Information that has System and Hidden attributes enabled; that's where your shadow copies are all stored. This volume is accessible only to the built-in system account on your server, not to administrators.
If your desktops are running Windows 2000 Professional (with Service Pack 3 or later) or Windows 98 Second Edition (SE), you need to download a different shadow-software client from the Microsoft Windows Download Center (http://www.microsoft.com/downloads/) and deploy it by using one of the methods described previously (you also have to install the same client software on the server). If your desktops are running Windows NT 4.0 Workstation or Windows Millennium Edition (ME), then you're out of luck.
The Previous Versions Client and the Shadow Copy Client provide the same functionality, but the Shadow Copy Client can be installed on multiple operating systems, such as Windows 2000 and Windows XP Professional, whereas the Previous Versions Client can only be installed on Windows XP Professional.
http://www.microsoft.com/technet/downloads/winsrvr/shadowcopyclient.mspx
If you're not even sure which file had that wonderful paragraph you wrote, but you know it's in the Budgets share, you could right-click on an empty area within the open share window, select Properties, and switch to the Previous Versions tab of the share itself. This displays all previous shadow copies made of that share and lets you view previous versions of individual files within the share, copy a previous version of all files in the share to another location, or roll back all files in the share to the specified previous version.
NTFS permissions change differently, depending on whether you copy a file or move it. So, in the case of shadow copies, if you restore a previous version of a file, it overwrites the original file in its original location but maintains the same NTFS permissions as the original file. But if you copy a previous version of a file to a different location on your drive, the copy inherits the permissions of the folder you copy it to.
In addition to poor planning and scheduling, resulting in insufficient disk space, there are a few other things you need to watch out for when implementing shadow copies. The first thing has to do with the block-based mechanism by which the VSS makes copies of changes made to files. If the filesystem cluster size is smaller than this block size, some of your shadow copies might disappear when you defragment your volume using the built-in Disk Defragmenter node in Computer Management. To prevent this from happening, always ensure that volumes on which shadow copies are stored have cluster sizes of 16 KB or greater. By default, on Windows Server 2003, any volumes larger than 2 GB will have a cluster size of only 4 KB, which is insufficient.
To solve this problem, when you format the volume, specify an allocation unit size of 16 KB instead using either Disk Management or the /a switch with the format command. On large volumes, you could use even higher cluster sizes of 32 or 64 KB. But if the volume will be used to store many small files, this can result in much wasted space on your drive. So, 16 KB is probably the optimal solution in most cases.
If you upgraded your server from Windows NT 4.0 Server and the volume was converted from FAT to NTFS by using the convert command, you're out of luck. Because convert always uses an allocation unit size of 512 bytes to optimally align with FAT filesystem boundaries, don't use a converted volume for storing shadow copies on a server. However, if your machine was previously running Windows 2000 Server, you might be in luck, because that platform allowed you to format FAT volumes with larger cluster sizes.
Best practice is usually to enable shadow copies on any volume where data files are stored, because the enhanced Backup utility included with Windows Server 2003 can back up open files on a volume on which shadow copies are enabled. That means that if users leave files open on their machines at night, the files can still be backed up instead of being locked and prevented from being backed up as in previous versions of Windows Backup. In this kind of scenario, it might be a good idea to schedule additional shadow copies to occur an hour or so before Backup is scheduled to run. You can also turn backing up of shadowed volumes on and off using the /SNAP switch in ntbackup, the command-line version of the Backup utility.
Don't enable shadow copies on a system or boot volume, because there have been reports of excessive generation of shadow copies. This causes poor system performance, especially on domain controllers where the contents of Active Directory is frequently updated. Programs that create many temporary files on these volumes can also cause shadow copies to grow quickly and fill up your volume if you give them enough room to do so, and a system volume that fills up is one that blue-screens.
If you accidentally delete any of the default hidden administrative shares on your server, you won't be able to enable shadow copies on any volumes on your machine. Re-enable Administrative shares to solve this problem.
Finally, before you delete a volume that has shadow copies enabled on it, disable shadow copies on the volume. If you don't, your event log might fill up with ID 7001 error messages, which can be annoying.
Setting the storage limit too small can adversely affect other programs, such as the Backup program in Windows Server 2003 and other backup programs that support the Volume Shadow Copy service. During the backup process, these programs create temporary shadow copies for consistent backups. The temporary shadow copies count towards the volume space limit you specify for shadow copies. If the available volume space remaining in the limit is too small, the Volume Shadow Copy service can delete existing shadow copies to free up space for the temporary shadow copy. If there are no existing shadow copies, and the volume space limit cannot accommodate the temporary shadow copy, the backup might fail.
Note, however, that NTFS compression is supported only if the cluster size is 4 KB or smaller.
If you plan to store the shadow copies on the same volume as the user files, note that a burst of disk I/O can cause all shadow copies to be deleted. If you cannot tolerate the sudden deletion of shadow copies, use a volume that will not be shadow copied, preferably on separate disks, for storing shadow copies.
To check the cluster size of a volume, use the fsutil fsinfo ntfsinfo command. If the volume contains data and you want to change the cluster size, you must back up the data on the volume, reformat it using the new cluster size, and then restore the data.
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Shadow Copies of Shared Folders and Distributed File Systems (DFS)
Using DFS to provide access to volumes that contain Shadow Copies
You can create DFS link targets on volumes that contain shadow copies, and
users can retrieve previous versions of files from the DFS link target, just
as they can from a regular shared folder. However, if you use multiple link
targets for a DFS link, each of those link targets can reside on a different
volume with its own shadow copies. As a result, the previous versions of
files can vary, depending on which link target the user last accesses to
change the file.
Explorer Problems on DFS based VSS
http://support.microsoft.com/kb/925066
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Converting Basic disks to Dynamic disks (with Shadow Copies of Shared Folders)
If the volumes that contain the original files and the shadow copy storage area
are on separate basic disks and you want to convert both of the disks to dynamic
disks, you must follow these directions:
• If the shadow copy storage area is not on the boot volume. First
dismount and take offline the volume that contains the original files.
To do this, use Mountvol.exe with the /p parameter. Next, convert the
disk that contains the storage area volume to a dynamic disk. After
the conversion, you have 20 minutes to mount the volume that contains
the original files and bring it online by using mountvol.exe or the
Disk Management snap-in; if you do not, you will lose the existing
shadow copies. After you bring the volume that contains the original
files back online, you can convert that disk to a dynamic disk.
• If the shadow copy storage area is on the boot volume. You can convert
the disk that contains the storage area volume to a dynamic disk
without having to dismount the volume that contains the original files.
To complete the conversion, you must restart the computer twice. Next,
convert the disk that contains the original files to a dynamic disk.
• Important:
If the disk that contains the original files is converted to a dynamic
disk first, the shadow copies are deleted when you convert the disk
that contains the storage area volume to a dynamic disk.